More Bad News For Fossil Fuels: Locomotives To Run On Green Hydrogen, Not Diesel
For all the attention given over to electric cars, a more sustainable approach would be to electrify mass transit and make it more accessible, affordable, and widespread. That’s a particularly tall order for railways, where diesel locomotives still command the field. That could soon change. The green hydrogen industry is gathering momentum, and it is opening up new opportunities to run diesel fuel off the rails.
Rail Decarbonization: It’s Complicated
In terms of electrifying mass transit, buses have been the low hanging fruit. Electric buses are becoming more commonplace, with batteries and hydrogen fuel cells both in the mix.
Wireless charging technology is further boosting the case for battery-electric buses. Earlier iterations required the vehicle to park, but new in-road charging systems will enable a battery-powered bus to keep moving along its route. Wireless in-road charging also enables fleet operators to deploy vehicles with smaller, less costly batteries.
The power situation is much more complicated for passenger and freight trains, where one locomotive, or sets of locomotives, need enough juice to pull a whole string of cars.
Many passenger lines are already fully electrified, through a connection with a stationary power source and overhead wires. Adding that system to routes without an overhead connection presents a next-level. Aside from any engineering obstacles, route electrification requires significant new investments in power infrastructure including transmission lines and substations.
The Green Hydrogen Solution
One alternative is to replace diesel fuel with another, more sustainable liquid fuel. Here in the US, for example, the Union Pacific railroad company has moved from a biofuel blend to a pilot test of 100% biofuel.
While potentially helpful in terms of global greenhouse gas emissions, the biofuel solution does not stop diesel locomotives from contributing to local air pollution. A zero-emission solution is needed, and hydrogen fuel cells have it. They produce electricity from a chemical reaction between hydrogen and oxygen. The only emission is water.
However, hydrogen presents the converse of the biofuel problem. Hydrogen fuel cells are a tailpipe solution for local pollution issues, but the sticky fingers of the global fossil fuel supply chain are all over hydrogen. Almost all hydrogen on the market today is extracted from natural gas or gasified coal.
An alternative is beginning to emerge in the form of green hydrogen, which is extracted from water in electrolysis systems that deploy electricity from renewable resources, and a catalyst (see more background on sustainable H2 here).
More Green Hydrogen Needed For Fuel Cell Locomotives
Here in the US, almost all diesel locomotives are partially electrified already, opening the door to retrofitting the entire fleet for full electrification.with either batteries or fuel cells, or a combination of both.
In a diesel-electric locomotive, diesel fuel is not used directly for locomotion. Instead, it is deployed in an on-board generator to run the train on electric drive, which serves as a fuel efficiency booster.
Installing a new fuel cell in a diesel-electric train is a complicated affair, but some momentum is beginning to build. California, for example, is trialing a retrofitted fuel cell switcher locomotive, aimed at reducing local emissions in rail freight yards. California is also introducing new purpose-built fuel cell passenger trainsets, from the Swiss firm Stadler.
Another fuel cell retrofit example comes from the North American rail firm CPKC, which has announced a joint venture with CSX to manufacture diesel-to-fuel cell retrofit kits in West Virginia (see more clean tech news from West Virginia here and here).
Yet to be answered is the question of the supply of green hydrogen needed to resolve both local and global greenhouse gas emissions. That’s not going to happen until green hydrogen is cost-competitive with its fossil-sourced counterpart. The US Department of Energy has set a goal of $1.00 per kilogram for green hydrogen against a current benchmark of $5.00. That’s far above the $2.00 (more or less) range for conventional hydrogen.
On the bright side, the green hydrogen gap is closing faster than some have anticipated, partly due to the availability of low-cost wind and solar power, along with cost and efficiency improvements in electrolyser technology. Supply chain scope and scale-up will also help bring costs down, with a healthy assist from government policy makers.
Gilding The Green Hydrogen Lily With Faster Fueling
Cost aside, green hydrogen alone does not resolve the question of whether or not diesel-dependent rail systems should convert to full battery power, fuel cells, or some combination of both.
One factor that can come into play is the time it takes to stop at a battery charging or hydrogen fuel station. In past years, fuel cell advocates could contrast long EV battery charging times with fuel cells, which can be refilled with hydrogen in a matter of minutes.
Between battery swapping and new fast-charging technology, that advantage is beginning to evaporate for passenger cars and other light duty vehicles.
The heavy duty field still offers opportunities for competition, and that’s where the French firm Lhyfe comes in. Last week, Lhyfe announced that it has completed a green hydrogen production plant in Germany, as the latest milestone in collaboration with Deutsche Bahn, the national railway of Germany.
The announcement involves a new production plant capable of producing up to 30 tons per year, supported by a 1-megawatt electrolyzer system installed at the Tübingen innovation hub run by Deutsche Bahn subsidiary DB Energie.
The green hydrogen will be used in a “climate-neutral” train. The new train will be tested on a route between Tübingen, Horb, and Pforzheim in Baden-Württemberg.
The Tübingen installation is Lhyfe’s first foray into Germany. If all goes according to plan, it won’t be the last. The Tübingen facility is part of Germany’s H2goesRail program, a partnership with Siemens Mobility, which aims to connect all the strands of the green hydrogen field — including fuel stations — into one seamless ecosystem.
“We aim to replace diesel multiple units in regional service and thus further reduce carbon emissions in rail transport,” Deutsche Bahn explains. “To achieve this, with H2goesRail we are developing an innovative mobile refueling station whose smart control unit will allow fast refueling of hydrogen trains.”
The hydrogen fuel stations are designed around a mobility model. The green hydrogen is produced on-site and stored in a mobile storage tank before undergoing further processing in a tank trailer, where the train will refuel.
“Lower energy consumption and shorter refueling times will be achieved through communication between the train and the refueling station and a pressure regulated refueling control system,” Deutsche Bahn explains.
“The innovative DB Energie tank station will refuel a hydrogen train in the same time as it would take to refuel a diesel train,” they add, for good measure.
Next Steps For Green Hydrogen
In an interesting twist, the H2Goes Rail deploys Siemens’s new Mireo plus H hydrogen fuel cell trainsets, which incorporate battery packs for an extra power boost. Siemens explains that the combination provides for a more efficient use of resources overall.
Either way, green hydrogen producers like Lyhfe are not depending solely on the transportation sector for support. Hydrogen is a ubiquitous input for various industrial processes and products. In particular, steelmakers and fertilizer producers are beginning to lean on green hydrogen to reduce their carbon footprints.
Keep an eye on Louisiana, which has been making some interesting moves that indicate an interest in attracting more hydrogen production to the state, without the fossil energy baggage.
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Image: A new, integrated ecosystem will deploy green hydrogen and mobile hydrogen fueling stations for fuel cell trains in Germany.
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